<html>
	<body>
		<img id="light" onclick="offaon()" src="lightoff.jpg">
		<script>
			function offaon()
			{
				elem=document.getElementById('light')
				if (elem.src.match("lighton"))
				{
					elem.src="lightoff.jpg";
				}
				else
				{
					elem.src="lighton.jpg";
				}
			}
		</script>
	</body>
</html>